The present invention relates generally to materials useful for tissue grafting, and in particular to such materials derived from extracellular matrices and retaining both collagen and substances such as growth factors that contribute to the beneficial properties of the materials. In one aspect, the invention relates to extracellular matrix tissue graft materials containing one or more growth factors modulated to a predetermined level, and related methods of manufacturing.
Extracellular matrix (ECM) materials, including those derived from submucosa and other tissues, are known tissue graft materials. See, e.g., U.S. Pat. Nos. 4,902,508, 4,956,178, 5,281,422, 5,372,821, 5,554,389, 6,099,567, and 6,206,931. Tissues from various biological structures can be used for these purposes, including for example small intestine, stomach, the urinary bladder, skin, pericardium, dura mater, fascia, and the like. These sources provide collagenous materials useful in a variety of surgical procedures where tissue support and/or ingrowth are desired.
Submucosa and other ECM materials have been shown to include a variety of components other than collagen that that can contribute to the bioactivity of the materials and to their value in medical grafting and other uses. As examples, ECM materials can include growth factors, cell adhesion proteins, and proteoglycans. However, ECM materials are typically subjected to a battery of manipulations in the manufacture of finished products containing them. This presents challenges in obtaining finished products that not only possess the necessary physical properties and appropriate levels of biocompatibility and sterility, but also the desired bioactivity. The present invention is addressed to these needs.